Fig. 6

Scoring of pathological changes. Gross and histologic changes in the spleen were scored based on the following standards: Gross lesion (0 for normal; 2.5 for atrophy without necrosis; 5 for enlarged and mottled; 7.5 for mild to moderate necrotic foci; 10 for extensive and severe necrosis); histologic changes (0 for normal; 2.5 for mild to moderate hyperplasia of lymphocytes; 5 for mild lymphocyte depletion; 7.5 for moderate (<50 %) lymphocyte depletion, histiocytic accumulation and necrosis; 10 for severe (>50 %) lymphocyte depletion, and extensive necrosis0. Average scores for three chickens were presented. Data were analyzed using One-way ANOVA followed by LSD multiple-comparison test. Lowercase letters on top of each stand for statistical difference, different letters mean a significant difference between two groups